doc: add installation instructions to README

[guisp03]

This pull request addresses issue #77 by adding a new section to the README.md with installation instructions for the game. The instructions include:

• Prerequisites, such as Python 3 and the Pygame engine.
• Step-by-step guidance for installing Pygame, covering both pip and alternative package managers (e.g., pacman for Arch-based systems).
• Instructions on how to clone the repository, navigate to the project folder, and run the game using the coral.py file.

These additions aim to provide a clear and accessible guide for new developers or users unfamiliar with Python and Pygame, ensuring an easier setup process.

[guisp03]

Hi @ImLusca , I’ve made the requested changes:

• Added the Python download link for Windows/Mac users.
• Included the apt install command for Linux users with a note on distribution differences.
• Updated the clone command to SSH. Let me know if there’s anything else to adjust. Thanks for the feedback!